The hydrotreating of hydrocarbon feed stocks containing carbon-sulfur bonds, carbon-nitrogen bonds and/or carbon-oxygen bonds is well known in the art. See for example, G. C. A. Schuit and B. C. Gates, A.I.Ch.E.J. 19(3), 419 (1973); S. C. Schuman and H. Shalit, Catalyst Review 4(2), 245 (1970).
Impregnation techniques for molten sulfur are known in other areas of technology, such as impregnation of ceramic bathroom tile and corrugated cardboard. See A.C.S. Adv. Chem. Ser. (110), 212-217 (1972).
West German Pat. No. 1,113,446 to BASF discloses the utilization of elemental sulfur and hydrogen to pretreat an alumina-supported cobalt molybdate catalyst which is employed in H.sub.2 S synthesis.
U.S. Pat. No. 3,424,782 to Nippon Oil shows the treatment of an ammoxidation catalyst with elemental sulfur and hydrogen to enhance the selectivity, but sulfur is continually added to the feed.
U.S. Pat. No. 3,563,912 to Union Oil discloses a method of preparing a nonpyrophoric sulfided catalyst for safe shipping and handling, wherein the partially sulfided catalyst is coated with paraffin or another sealant, the sealant containing encapsulated sulfur or a sulfur-containing compound.
U.S. Pat. No. 3,453,217 to Chevron discloses a sulfided catalyst which is coated with a hydrocarbon to protect it from the atmosphere. More than 5 wt. % of the metal sulfides are converted to other compounds in this process.
U.S. Pat. No. 4,014,815 to Exxon discloses a process for regenerating spent metal catalysts by treatment with a sulfurous atmosphere at a pressure of at least 0.10 atmospheres and at a controlled high temperature of between 400.degree.-825.degree. C., preferably between 400.degree.-715.degree. C., and most preferably between 400.degree.-600.degree. C., for a time sufficient for the selective formation of sulfides of carbon and sulfides of vanadium or lead which sulfides are characterized by having high volatility and solubility in the sulfurous atmosphere and which vanadium and carbon sulfides are selectively removed from the catalyst within the stated temperature range.
U.S. Pat. No. 4,048,058 to Standard Oil (Indiana) discloses that multimetallic reforming catalysts are sulfided at 350.degree.-470.degree. C. in a stream of light hydrocarbons, rich in hydrogen, by injecting sulfur compound into the stream, upstream from the catalyst, and continuing the treatment to provide on the catalyst 0.1 to 2.5 moles sulfur/mole total active metal.